This invention relates to an apparatus and method for aligning couplings of rotating shafts, particularly large, high speed shafts such as used in electric power plants and other large industrial operations. Manufacturers of high speed rotating equipment provide specifications for desired alignment and limits of deviation. Operation outside of these recommended norms can cause damage to equipment, vibration and other problems. Manufacturers also require a process that rotates both shafts to record the alignment relationship between the two rotors. Each rotor can be rotated separately or the rotors can be temporarily connected with soft metal pins. The rotation of each coupling separately requires additional time to rotate each rotor. Connecting pins cause deflection of the couplings due to binding with time required to free the pins. Neither process will stop the coupling rims with the correct degree position to allow use of new laser alignment tooling that is now available. The cam pin according to the present invention, when used without the cam sleeve according to the present invention, provides a process to record coupling alignment readings that are free of errors due to deflection of the couplings and stops the rims with the degree of relationship required for the use of laser tooling. The cam pin and sleeve used together provides a process that is safer and faster than the other processes. Prior art methods include use of a crane to rotate the shafts, and while this process can be acceptable from an accuracy standpoint, the process can frequently cause accidents. The time required to complete alignment and assemble couplings effects the time the equipment is out of service, and should therefore be reduced to a minimum. Another prior art device, referred to as a "Hutter" turning pin, uses a pin which is split so that it separates into two halves for insertion and removal from the rotor couplings for aligning the rotors. A Hutter coupling runout eliminator pin corrects differential runout prior to line boring and aligns coupling bolt holes in a manner similar to the turning pins.
Use of the cam pin and sleeve according to the invention shortens the time that equipment must be out of service for alignment.
With tandem rotors, all of the rotors can be connected with a cam pin in each coupling and the shafts all rotated together. The cam pins are unlocked at each data point to assure that the data is not corrupted by binding, and then locked again for the next rotation. The rotors can be rotated with drive equipment supplied by the manufacturer or any other suitable device that can impart slow, even rotation to the rotors.